D-Calib: Calibration Software for Multiple Cameras System
|
|
- Lawrence Curtis
- 6 years ago
- Views:
Transcription
1 D-Calib: Calibration Software for Multiple Cameras Sstem uko Uematsu Tomoaki Teshima Hideo Saito Keio Universit okohama Japan {u-ko tomoaki Cao Honghua Librar Inc. Japan Abstract This paper presents calibration software D-Calib for multiple cameras which can calibrate all cameras at the same time with eas operation. Our calibration method consists of two steps: initialization of camera parameters using planar marker pattern optimization of initial parameters b tracking two markers attached to a wand. B weak calibration and multi-stereo reconstruction b multiple cameras the initial parameters can be optimized in spite of few markers. Even if the cameras are placed in a large space the calibration can be achieved b swinging the wand around the space. This method is completed as commercial software which achieves 0.7 % of average errors against the marker pattern size. Introduction Estimation process of camera s unique parameters (such as focal length and skew parameters is called as camera calibration [4]. This calibration process is ver important issue for 3D reconstruction 3D motion capture and virtualized environment etc. [3 5]. DLT (Direct Linear Transformation method is commonl used as the tpical calibration method []. In DLT method multiple markers whose 3D coordinates are alread known are captured with a camera. Using the pairs of D coordinates in the captured images and known 3D coordinates of the markers twelve camera parameters (DOF is eleven are computed b least-square-method. For using DLT method in large space it is necessar to place the markers to cover the overall space. Increasing the number of markers is also necessar to improve the accurac of the calibration. However setting up the markers whose 3D coordinates is known in the large space takes amount of time and effort. Using a lot of cameras there is also a big problem to place the markers so that all of them can be captured in field of view of the camera and the do not occlude each other. Moreover it often happens that a user has to click the displa to assign D coordinates of markers. Therefore it involves a lot of effort and time when increasing the number of markers and cameras. hang proposed a eas calibration sstem based on a moving plane where checker pattern is drawn [8]. This calibration method does not need 3D calibration objects with known 3D coordinates. However since the calibration plane is not visible in all cameras the user has to move the plane in front of each camera. Moreover the sstem can calibrate onl part of the space. Therefore this sstem is not suite for using multiple cameras. Svoboda et al. proposed a calibration method for multiple cameras using one bright point like a laser pointer [7]. The point in the captured images are detected and verified b a robust RANSAC. The structures of the projected points are reconstructed b factorization. These computations can be automaticall done. Since one point is used as a calibration object however onl re-projection errors are evaluated in their method. In this paper we introduce calibration software D- Calib designed for multiple cameras using in a large space []. In this software we can estimate the camera parameters of all cameras at the same time b using a square pattern with si spheral markers and a wand with two spheral markers. After capturing one frame of the square pattern the wand swinging in the whole of space is captured for a few hundreds of frames. Therefore we do not have to set up a lot of markers around the space. The spheral markers are made b retroreflective materials so that the can be successfull detected from the captured images. Since all the processes are automaticall performed b image processing technique without manual operations the user s task is etremel reduced. In our method initial parameters computed from the square pattern are optimized b using the two markers attached to the wand. Since the distance between the markers is known we can also optimize 3D reconstruction errors in addition to D re-projection errors which are onl accurac evaluation in Svoboda s method. 4th International Conference on Image Analsis and Processing (ICIAP /07 $
2 Input images Cam Cam Cam n Binarization & Labeling Detect markers Input images Cam Cam Cam n Binarization & Labeling Track & Identif Markers Calc homograph Calc D errors Calc 3D errors Estimate init params. Optimization Estimation of initial parameters p p p 34 p' p' p' 34 Optimization of initial parameters Figure. Flowchart of calibration process. Camera Calibration The relationship between the 3D real world ( and the D image ( is represented as a following equation. P p p p 3 p 4 p p p 3 p 4 p 3 p 3 p 33 p 34 ( This 3 4 matri P is called as a projection matri and the twelve elements of the matri are called as camera parameters. Estimation of these camera parameters corresponds to camera calibration. In our software the twelve camera parameters are computed for each camera. Since we focus on computing accurate etrinsic parameters of multiple cameras we assume that intrinsic parameters of the cameras are previousl given b using other method. If using uncalibrated cameras the intrinsic parameters are approimated b simple form without skew and distortion parameters as described in Sec. A.. 3 Our Calibration Method Fig. shows the flowchart of the calibration method in our software. This method consists of two steps: ( estimation of initial parameters ( optimization of initial parameters. In the estimation of initial parameters a square pattern with si spheral markers is placed on the floor and is captured b multiple cameras as shown in Fig. (a. The real positions of the spheral markers on the square pattern are previousl known. Using the relationship between the D positions of the markers in captured images and the 3D positions on the markers camera parameters are computed for each camera as initial parameters. These camera parameters represent twelve elements of a projection matri P as described in Sec.. Actuall the etrinsic parameters of each camera are computed from the square pattern and combined with the intrinsic parameters obtained in advance into the camera parameters. Since the initial parameters are computed from the square planar pattern the accurac against perpendicular direction to the plane is relativel small compared with the other directions. Moreover high calibration accurac can be obtained onl in the area close to the square pattern. Therefore the initial parameters of ever camera should be improved b the optimization at the same time in the net square pattern P P P 3 (a Capturing images for estimation of initial parameters. wand P' P' P' 3 (b Capturing images for optimization of initial parameters. Figure. Sstem environments in our software. 4th International Conference on Image Analsis and Processing (ICIAP /07 $
3 step. In the optimization step we collect a hundreds of frames captured in the multiple cameras as shown in Fig. (b while a wand that has two spheral markers is swung in the entire object space. The positions of the two spheral markers are detected and tracked from the captured image sequences of ever camera. Since all the spheral markers are made b retroreflective materials the can be easil detected from the captured images. B evaluating the estimated etrinsic parameters with epipolar constraints of tracked markers and the 3D distance between the two markers on the wand the parameters are optimized. 3. Estimation of Initial Parameters A square pattern with si spheral markers is placed on the floor. Then images of the square markers are captured b multiple cameras. From each captured image the si markers D coordinates are detected as ( ( 6 6. We assume that the plane of the square pattern is - plane in the 3D coordinate. Then we define 3D coordinates of the si markers as ( 0 ( Based on this definition the relationship between the D and 3D coordinates of the markers can be represented b using a 3 3 planar transformation matri (Homograph H as following equation. ( i 6 i i H i i h h h 3 h h h 3 h 3 h 3 h 33 i i ( This equation is equivalent to eq. ( in Sec. when = 0 in eq. (. This means that H provides the first second and fourth column vectors of the projection matri P. H is a matri which transfers points between the planes and is easil computed b more than four corresponding points on both of the planes. Accordingl we compute H between the 3D plane (- plane and the D plane (- plane from si corresponding points which are the spheral markers of the square pattern. Then the twelve camera parameters of each camera Figure 3. Corresponding of planes b homograph. H are computed from H. The detail of the computing process will be described in Sec. A. 3. Optimization of Initial Parameters In this process we define an error function consisting of D re-projection errors and 3D reconstruction errors which is used for optimizing the initial parameters b minimizing the function. As shown in Fig. (b the images of the swinging wand with two spherical markers are captured for a hundreds frames b the multiple cameras. B detecting and tracking the two spheral markers from the captured image sequences we can obtain a set of D-D corresponding points between the cameras which provides epipolar relationship among the cameras. Using this data set we can compute D re-projection errors of the initial camera parameters which are evaluated b the distance between the point of the marker in the image and the re-projected epipolar line onto the other cameras. Since the 3D distance between the two markers on the wand are known we also evaluate the accurac of the initial camera parameters b comparing the 3D distance between two marker positions recovered from the input images with the real distance between them. 3.. Tracking of Markers After binarization and labeling are performed to the captured image sequence from each camera two spheral markers regions are detected from each image. For tracking the two markers each marker must be identified through the image sequence. The identification of each marker is performed b computing the distance of the positions between the previous frame and the net frame. The marker with the closest position to the position in the previous frame is identified as the same marker. Even though the two markers are occluded each other or are not detected in some frames each marker can be continuousl tracked b using direction of marker s movement. Therefore the cameras do not have to see all the markers through the captured images. Onl the frames which are captured when the markers are visible in all cameras are automaticall selected as a data set of D-D correspondences. 3.. Optimization Using the D coordinates of the tracked markers two kinds of errors are computed; (a D re-projection errors ɛ (b 3D reconstruction errors ɛ. Error function is defined as eq. (3 and minimized b Down-hill simple method to optimize the si etrinsic parameters included in the initial 4th International Conference on Image Analsis and Processing (ICIAP /07 $
4 camera parameters; rotation (3 DOF: θ φ ψ translation (3 DOF: t t t z. If all cameras have the same intrinsic parameters it is possible to optimize seven parameters including the focal length f. This is because D re-projection errors are not absolute but relative values among the cameras. { cost(θ φψ t t t z = (ɛ + ɛ cost(θ φψ t t t z f = (ɛ + ɛ D re-projection errors ɛ When a set of D-D correspondences between two cameras is known a point in the image captured b the camera is projected onto the image captured b the camera as a line and should eist anwhere on the line. This is called as epipolar constraints and the line is called as epipolar line. The marker in the image of the camera is projected onto the image of the camera as a line (epipolar line b the initial camera parameters as shown in Fig. 4(a. The epipolar line should be projected on the position of the marker which is captured b the camera however it might be projected awa from the marker because of the P P C C Cam Cam c c c epipolar line d (a Errors from epipolar constraints. Cam (base camera (3 errors included in the initial parameters. Therefore the distance between the epipolar line and the marker in the image of camera is defined as a D re-projection error from the camera to the camera. In the same wa D re-projection errors are computed mutuall among all the cameras and then the sum of them becomes ɛ. Here the D re-projection errors are computed using epipolar constraints which represent relative geometr between the cameras. Therefore we define one camera as an absolute basis and do not compute the re-projection errors to the base camera as shown in Fig. 4(b. 3D reconstruction errors ɛ When camera parameters of two cameras are known 3D coordinates of an object which is captured b the cameras can be reconstructed b using triangulation from D coordinates in the images. In our method 3D reconstruction errors ɛ are computed b multi-stereo reconstruction of multiple cameras. When the two markers are captured b each camera as shown in Fig. 5 3D coordinates of the markers can be obtained b triangulation from the D coordinates in each image (see Sec. B. Computing the 3D coordinates of the markers from all the cameras 3D distance D between the markers can be computed. Since the real distance s is known the difference between D and s becomes a 3D reconstruction error at ever frame and then the sum of them becomes ɛ. ɛ = frame (D s After computing ɛ and ɛ the initial parameters are optimized b minimizing the error function of eq. (3 b Down-hill simple method. 4 Eperimental Results In this section we will show two eperimental results of our calibration software; four cameras configuration and ( (4 Cam Cam 3 Cam 4 s D ( P P ( ( ( ( (b Relationship of projection between cameras. Figure 4. Computation of D re-projection errors. Figure 5. Computation of 3D reconstruction errors. 4th International Conference on Image Analsis and Processing (ICIAP /07 $
5 Table. Evaluation results from optimized parameters. (a Square pattern of markers (b Wand Figure 6. Markers used in our software. numbers of cameras Minimum error [mm] Maimum error [mm] Average error [mm] Standard deviation Size of [mm] calibrated [mm] space [mm] Table. Comparison of results between initial and optimized parameters. Minimum error [mm] Maimum error [mm] Average error [mm] Standard deviation Figure 7. 3D coordinate sstem defined b initial parameters. Figure 8. Tracking results of two markers of wand. si cameras configuration. In both of the eperiments the square pattern with si markers is captured at one frame b each camera to estimate initial camera parameters as shown in Fig. 6(a. Net the wand swinging in the space is captured for 00 frames b each camera as shown in Fig. 6(b. The size of the space where the wand is swinging is about m m m. In both of the eperiments the size of square pattern marker is [mm] the distance between the two markers on the wand is 50 [mm]. The resolution of the captured image is Fig. 7 shows the results of - - coordinate sstems 4th International Conference on Image Analsis and Processing (ICIAP /07 $ initial optimized defined b initial parameters estimated b four cameras. Fig. 8 shows the tracking results of two markers which are attached to the wand b the four cameras. We can see that the two markers are successfull detected and tracked through the captured image sequence without confusing the markers b our tracking method. Table shows the evaluation results of errors obtained b optimization of the initial parameters using the tracked markers. These errors represent 3D reconstruction errors which are computed using optimized camera parameters instead of the initial parameters in the same wa described in Sec The error is computed at ever frame in the captured image sequence and then minimum maimum and average values and standard deviation of the computed errors are listed in Table. Table shows each error computed b using the initial and the optimized parameters. From Tab. we can find that the minimum errors are less than 0. [mm] and the maimum error is also about 4.6 [mm]. These results can be considered small enough compared to the size of the space. The errors included in the initial parameters can be reduced b our optimization method as shown in Tab.. Moreover the standard deviation shows that the space can be impartiall calibrated b swinging the wand around the space. 5 Conclusions In this paper we proposed calibration software for multiple cameras. The camera parameters of all the cameras can
6 be estimated at the same time. Since all the processing of this software can be automaticall performed without user s manual operations like a assigning the marker s positions b clicking the displa the user can easil use this software. This software can calibrate a lot of cameras which are placed in large space without placing man markers around the space in advance. Therefore it is well suited for the task which needs large space like 3D motion capture. A Calculation P from H A projection matri consists of intrinsic and etrinsic parameters. Therefore we obtain a projection matri b computing the intrinsic and the etrinsic parameters from the homograph and combining them [6]. We define intrinsic parameters a rotation matri and a translation vector of etrinsic parameters as A R and t. Then a projection matri P will be P = A [R t] = A [r r r 3 t] (5 A = f 0 c 0 f c 0 0 (6 r r r 3 are column vectors of the rotation matri R f is the focal length (c c is a center of the image. From eq. ( P = A [r r t] = H = h h h 3 h h h 3 h 3 h 3 h 33 (7 A H = [r r t] (8 Using the homograph H computed from si corresponding points of spheral markers the intrinsic and etrinsic parameters are computed from eq. (8. When both the intrinsic and etrinsic parameters are obtained the projection matri P is obtained b (5. A. Computation of Intrinsic Parameters When using uncalibrated cameras intrinsic parameters of the cameras have to be computed. Since we define A as eq. (6 we onl have to obtain a focal length f. Using the propert of the rotation matri R that inner product of r and r is 0 f is obtained b developing eq. (8 as follows. f = (h c h 3 (h c h 3 h 3 h 3 + (h c h 3 (h c h 3 h 3 h 3 (9 A. Computation of Etrinsic Parameters The first and second column vectors r r of the rotation matri R and the translation vector t are alread obtained when H is computed from eq. (8. Therefore we onl have to compute the third column vector r 3 of R. Also using the propert of R that the cross product of r and r becomes r 3 we obtain it as follows. B R = [r r r 3 ] = [r r (r r ] (0 Multi-Stereo Reconstruction When camera parameters of multiple cameras are known a 3D coordinate of a point ( can be computed from following equation using D coordinates of the corresponding points ( i i in each camera. (p 3 p (p 3 p (p 33 p 3 (p 3 p (p 3 p (p 33 p 3. (p n 3 n p n (p n 3 n p n (p n 33 n p n 3 (p n 3 n p n (p n 3 n p n (p n 33 n p n 3 References = p 4 p 34 p 4 p 34 p n 4 p n 34 n p n 4 p n 34 n ( [] []. I. Abdel-Aziz and H. M. Karara. Direct linear transformation from comparator coordinates into object space coordinates in close-range photogrammetr. In Proc. of Smposium on Close-Range Photogrammetr pages [3] G. K. M. Cheung S. Baker and T. Kanade. Shape-fromsilhouette of articulated objects and its use for human bod kinematics estimation and motion capture. In Proc. of Computer Vision and Pattern Recognition pages June 003. [4] R. Hartle and A. isserman. Multiple View Geometr in computer vision. CAMBRIDGE UNIVERSIT PRESS 000. [5] H. Saito S. Baba and T. Kanade. Appearance-based virtual view generation from multi-camera videos captured in the 3d room. IEEE Transactions on Multimedia 5(3: September 00. [6] G. Simon A. Fitzgibbon and A. isserman. Markerless tracking using planar structures in the scene. In Proc. of the ISAR pages [7] T. Svoboda D. Martinec and T. Pajdla. A convenient multicamera self-calibration for virtual environments. Presence 4(4:407 4 August 005. [8]. hang. A fleible new technique for camera calibration. IEEE Transactions on Pattern Analsis and Machine Intelligence (: th International Conference on Image Analsis and Processing (ICIAP /07 $
Epipolar Constraint. Epipolar Lines. Epipolar Geometry. Another look (with math).
Epipolar Constraint Epipolar Lines Potential 3d points Red point - fied => Blue point lies on a line There are 3 degrees of freedom in the position of a point in space; there are four DOF for image points
More informationWorld Academy of Science, Engineering and Technology International Journal of Computer and Information Engineering Vol:10, No:4, 2016
World Academ of Science, Engineering and Technolog X-Corner Detection for Camera Calibration Using Saddle Points Abdulrahman S. Alturki, John S. Loomis Abstract This paper discusses a corner detection
More informationVision-Based Registration for Augmented Reality with Integration of Arbitrary Multiple Planes
Vision-Based Registration for Augmented Reality with Integration of Arbitrary Multiple Planes Yuo Uematsu and Hideo Saito Keio University, Dept. of Information and Computer Science, Yoohama, Japan {yu-o,
More information3D Geometry and Camera Calibration
3D Geometr and Camera Calibration 3D Coordinate Sstems Right-handed vs. left-handed 2D Coordinate Sstems ais up vs. ais down Origin at center vs. corner Will often write (u, v) for image coordinates v
More informationMultibody Motion Estimation and Segmentation from Multiple Central Panoramic Views
Multibod Motion Estimation and Segmentation from Multiple Central Panoramic Views Omid Shakernia René Vidal Shankar Sastr Department of Electrical Engineering & Computer Sciences Universit of California
More informationA Practical Camera Calibration System on Mobile Phones
Advanced Science and echnolog Letters Vol.7 (Culture and Contents echnolog 0), pp.6-0 http://dx.doi.org/0.57/astl.0.7. A Practical Camera Calibration Sstem on Mobile Phones Lu Bo, aegkeun hangbo Department
More informationCS 2770: Intro to Computer Vision. Multiple Views. Prof. Adriana Kovashka University of Pittsburgh March 14, 2017
CS 277: Intro to Computer Vision Multiple Views Prof. Adriana Kovashka Universit of Pittsburgh March 4, 27 Plan for toda Affine and projective image transformations Homographies and image mosaics Stereo
More informationCalibration and measurement reconstruction
Scuola universitaria professionale della Svizzera italiana Dipartimento Tecnologie Innovative Metrolog laborator Calibration and measurement reconstruction Scope Tasks - Calibration of a two-degree-of-freedom
More informationMAN-522: COMPUTER VISION SET-2 Projections and Camera Calibration
MAN-522: COMPUTER VISION SET-2 Projections and Camera Calibration Image formation How are objects in the world captured in an image? Phsical parameters of image formation Geometric Tpe of projection Camera
More informationProposal of a Touch Panel Like Operation Method For Presentation with a Projector Using Laser Pointer
Proposal of a Touch Panel Like Operation Method For Presentation with a Projector Using Laser Pointer Yua Kawahara a,* and Lifeng Zhang a a Kushu Institute of Technolog, 1-1 Sensui-cho Tobata-ku, Kitakushu
More information3D Corner Detection from Room Environment Using the Handy Video Camera
3D Corner Detection from Room Environment Using the Handy Video Camera Ryo HIROSE, Hideo SAITO and Masaaki MOCHIMARU : Graduated School of Science and Technology, Keio University, Japan {ryo, saito}@ozawa.ics.keio.ac.jp
More informationPlayer Viewpoint Video Synthesis Using Multiple Cameras
Player Viewpoint Video Synthesis Using Multiple Cameras Kenji Kimura *, Hideo Saito Department of Information and Computer Science Keio University, Yokohama, Japan * k-kimura@ozawa.ics.keio.ac.jp, saito@ozawa.ics.keio.ac.jp
More informationExploiting Rolling Shutter Distortions for Simultaneous Object Pose and Velocity Computation Using a Single View
Eploiting Rolling Shutter Distortions for Simultaneous Object Pose and Velocit Computation Using a Single View Omar Ait-Aider, Nicolas Andreff, Jean Marc Lavest and Philippe Martinet Blaise Pascal Universit
More informationA rigid body free to move in a reference frame will, in the general case, have complex motion, which is simultaneously a combination of rotation and
050389 - Analtical Elements of Mechanisms Introduction. Degrees of Freedom he number of degrees of freedom (DOF) of a sstem is equal to the number of independent parameters (measurements) that are needed
More informationSOFTWARE APPLICATION FOR CALIBRATION OF STEREOSCOPIC CAMERA SETUPS
Metrol. Meas. Sst., Vol. XIX (212), No. 4, pp. 85-816. METROLOGY AND MEASUREMENT SYSTEMS Inde 3393, ISSN 86-8229 www.metrolog.pg.gda.pl SOFTWARE APPLICATION FOR CALIBRATION OF STEREOSCOPIC CAMERA SETUPS
More information1. We ll look at: Types of geometrical transformation. Vector and matrix representations
Tob Howard COMP272 Computer Graphics and Image Processing 3: Transformations Tob.Howard@manchester.ac.uk Introduction We ll look at: Tpes of geometrical transformation Vector and matri representations
More informationStructure from motion
Structure from motion Structure from motion Given a set of corresponding points in two or more images, compute the camera parameters and the 3D point coordinates?? R 1,t 1 R 2,t 2 R 3,t 3 Camera 1 Camera
More information3D Photography: Epipolar geometry
3D Photograph: Epipolar geometr Kalin Kolev, Marc Pollefes Spring 203 http://cvg.ethz.ch/teaching/203spring/3dphoto/ Schedule (tentative) Feb 8 Feb 25 Mar 4 Mar Mar 8 Mar 25 Apr Apr 8 Apr 5 Apr 22 Apr
More informationStructure from Motion. Introduction to Computer Vision CSE 152 Lecture 10
Structure from Motion CSE 152 Lecture 10 Announcements Homework 3 is due May 9, 11:59 PM Reading: Chapter 8: Structure from Motion Optional: Multiple View Geometry in Computer Vision, 2nd edition, Hartley
More informationX y. f(x,y,d) f(x,y,d) Peak. Motion stereo space. parameter space. (x,y,d) Motion stereo space. Parameter space. Motion stereo space.
3D Shape Measurement of Unerwater Objects Using Motion Stereo Hieo SAITO Hirofumi KAWAMURA Masato NAKAJIMA Department of Electrical Engineering, Keio Universit 3-14-1Hioshi Kouhoku-ku Yokohama 223, Japan
More informationarxiv: v1 [cs.cv] 28 Sep 2018
Camera Pose Estimation from Sequence of Calibrated Images arxiv:1809.11066v1 [cs.cv] 28 Sep 2018 Jacek Komorowski 1 and Przemyslaw Rokita 2 1 Maria Curie-Sklodowska University, Institute of Computer Science,
More informationAn Optimized Sub-texture Mapping Technique for an Arbitrary Texture Considering Topology Relations
An Optimied Sub-teture Mapping Technique for an Arbitrar Teture Considering Topolog Relations Sangong Lee 1, Cheonshik Kim 2, and Seongah Chin 3,* 1 Department of Computer Science and Engineering, Korea
More informationImprovement of Accuracy for 2D Marker-Based Tracking Using Particle Filter
17th International Conference on Artificial Reality and Telexistence 2007 Improvement of Accuracy for 2D Marker-Based Tracking Using Particle Filter Yuko Uematsu Hideo Saito Keio University 3-14-1 Hiyoshi,
More informationDIGITAL ORTHOPHOTO GENERATION
DIGITAL ORTHOPHOTO GENERATION Manuel JAUREGUI, José VÍLCHE, Leira CHACÓN. Universit of Los Andes, Venezuela Engineering Facult, Photogramdemr Institute, Email leirac@ing.ula.ven Working Group IV/2 KEY
More informationGeometry of image formation
Geometr of image formation Tomáš Svoboda, svoboda@cmp.felk.cvut.c ech Technical Universit in Prague, enter for Machine Perception http://cmp.felk.cvut.c Last update: November 0, 2008 Talk Outline Pinhole
More informationTwo Dimensional Viewing
Two Dimensional Viewing Dr. S.M. Malaek Assistant: M. Younesi Two Dimensional Viewing Basic Interactive Programming Basic Interactive Programming User controls contents, structure, and appearance of objects
More informationNon-Euclidean Spring Embedders
Non-Euclidean Spring Embedders Stephen G. Kobourov Universit of Arizona Kevin Wampler Universit of Arizona Abstract We present a method b which force-directed algorithms for graph laouts can be generalized
More information3D Sensing. Translation and Scaling in 3D. Rotation about Arbitrary Axis. Rotation in 3D is about an axis
3D Sensing Camera Model: Recall there are 5 Different Frames of Reference c Camera Model and 3D Transformations Camera Calibration (Tsai s Method) Depth from General Stereo (overview) Pose Estimation from
More informationcalibrated coordinates Linear transformation pixel coordinates
1 calibrated coordinates Linear transformation pixel coordinates 2 Calibration with a rig Uncalibrated epipolar geometry Ambiguities in image formation Stratified reconstruction Autocalibration with partial
More informationImage Metamorphosis By Affine Transformations
Image Metamorphosis B Affine Transformations Tim Mers and Peter Spiegel December 16, 2005 Abstract Among the man was to manipulate an image is a technique known as morphing. Image morphing is a special
More informationStructure from motion
Structure from motion Structure from motion Given a set of corresponding points in two or more images, compute the camera parameters and the 3D point coordinates?? R 1,t 1 R 2,t R 2 3,t 3 Camera 1 Camera
More informationCS231M Mobile Computer Vision Structure from motion
CS231M Mobile Computer Vision Structure from motion - Cameras - Epipolar geometry - Structure from motion Pinhole camera Pinhole perspective projection f o f = focal length o = center of the camera z y
More informationA Desktop 3D Scanner Exploiting Rotation and Visual Rectification of Laser Profiles
A Desktop 3D Scanner Exploiting Rotation and Visual Rectification of Laser Profiles Carlo Colombo, Dario Comanducci, and Alberto Del Bimbo Dipartimento di Sistemi ed Informatica Via S. Marta 3, I-5139
More informationComputer Vision Lecture 20
Computer Vision Lecture 2 Motion and Optical Flow Bastian Leibe RWTH Aachen http://www.vision.rwth-aachen.de leibe@vision.rwth-aachen.de 28.1.216 Man slides adapted from K. Grauman, S. Seitz, R. Szeliski,
More informationLUMS Mine Detector Project
LUMS Mine Detector Project Using visual information to control a robot (Hutchinson et al. 1996). Vision may or may not be used in the feedback loop. Visual (image based) features such as points, lines
More informationOn the Kinematics of Undulator Girder Motion
LCLS-TN-09-02 On the Kinematics of Undulator Girder Motion J. Welch March 23, 2010 The theor of rigid bod kinematics is used to derive equations that govern the control and measurement of the position
More informationImage Formation. 2. Camera Geometry. Focal Length, Field Of View. Pinhole Camera Model. Computer Vision. Zoltan Kato
Image Formation 2. amera Geometr omuter Vision oltan Kato htt://www.in.u-seged.hu/~kato seged.hu/~kato/ 3D Scene Surace Light (Energ) Source inhole Lens Imaging lane World Otics Sensor Signal amera: Sec
More informationPerspective Projection Transformation
Perspective Projection Transformation Where does a point of a scene appear in an image?? p p Transformation in 3 steps:. scene coordinates => camera coordinates. projection of camera coordinates into image
More informationPrecision Peg-in-Hole Assembly Strategy Using Force-Guided Robot
3rd International Conference on Machiner, Materials and Information Technolog Applications (ICMMITA 2015) Precision Peg-in-Hole Assembl Strateg Using Force-Guided Robot Yin u a, Yue Hu b, Lei Hu c BeiHang
More informationLocation-based augmented reality on cellphones
Location-based augmented realit on cellphones Ma 4th 009 October 30th 009 PAUCHER Rémi Advisor : Matthew Turk Plan Overview... 3 Internship subject and first impressions... 3 Motivations about such an
More informationStereo and Epipolar geometry
Previously Image Primitives (feature points, lines, contours) Today: Stereo and Epipolar geometry How to match primitives between two (multiple) views) Goals: 3D reconstruction, recognition Jana Kosecka
More informationA Method to Measure Eye-Hand Coordination for Extracting Skilled Elements-Simultaneous Measurement of Eye-Gaze and Hand Location-
Computer Technolog and Application 5 (214) 73-82 D DAVID PUBLISHING A Method to Measure Ee-Hand Coordination for Extracting Skilled Elements-Simultaneous Measurement of Ee-Gaze and Hand Location- Atsuo
More informationMAPI Computer Vision
MAPI Computer Vision Multiple View Geometry In tis module we intend to present several tecniques in te domain of te 3D vision Manuel Joao University of Mino Dep Industrial Electronics - Applications -
More informationDepth. Common Classification Tasks. Example: AlexNet. Another Example: Inception. Another Example: Inception. Depth
Common Classification Tasks Recognition of individual objects/faces Analyze object-specific features (e.g., key points) Train with images from different viewing angles Recognition of object classes Analyze
More informationComputing F class 13. Multiple View Geometry. Comp Marc Pollefeys
Computing F class 3 Multiple View Geometr Comp 90-089 Marc Pollefes Multiple View Geometr course schedule (subject to change) Jan. 7, 9 Intro & motivation Projective D Geometr Jan. 4, 6 (no class) Projective
More informationDisparity Fusion Using Depth and Stereo Cameras for Accurate Stereo Correspondence
Disparit Fusion Using Depth and Stereo Cameras for Accurate Stereo Correspondence Woo-Seok Jang and Yo-Sung Ho Gwangju Institute of Science and Technolog GIST 123 Cheomdan-gwagiro Buk-gu Gwangju 500-712
More informationFlexible Calibration of a Portable Structured Light System through Surface Plane
Vol. 34, No. 11 ACTA AUTOMATICA SINICA November, 2008 Flexible Calibration of a Portable Structured Light System through Surface Plane GAO Wei 1 WANG Liang 1 HU Zhan-Yi 1 Abstract For a portable structured
More informationGeneral Terms Algorithms, Measurement, Design.
Smart Camera Network Localization Using a 3D Target John Kassebaum, Nirupama Bulusu, Wu-Chi Feng Portland State Universit {kassebaj, nbulusu, wuchi}@cs.pd.edu ABSTRACT We propose a new method to localize
More informationVision-based Real-time Road Detection in Urban Traffic
Vision-based Real-time Road Detection in Urban Traffic Jiane Lu *, Ming Yang, Hong Wang, Bo Zhang State Ke Laborator of Intelligent Technolog and Sstems, Tsinghua Universit, CHINA ABSTRACT Road detection
More information3D Environment Measurement Using Binocular Stereo and Motion Stereo by Mobile Robot with Omnidirectional Stereo Camera
3D Environment Measurement Using Binocular Stereo and Motion Stereo by Mobile Robot with Omnidirectional Stereo Camera Shinichi GOTO Department of Mechanical Engineering Shizuoka University 3-5-1 Johoku,
More information12.4 The Ellipse. Standard Form of an Ellipse Centered at (0, 0) (0, b) (0, -b) center
. The Ellipse The net one of our conic sections we would like to discuss is the ellipse. We will start b looking at the ellipse centered at the origin and then move it awa from the origin. Standard Form
More informationLecture 9: Epipolar Geometry
Lecture 9: Epipolar Geometry Professor Fei Fei Li Stanford Vision Lab 1 What we will learn today? Why is stereo useful? Epipolar constraints Essential and fundamental matrix Estimating F (Problem Set 2
More informationKINEMATICS STUDY AND WORKING SIMULATION OF THE SELF- ERECTION MECHANISM OF A SELF-ERECTING TOWER CRANE, USING NUMERICAL AND ANALYTICAL METHODS
The rd International Conference on Computational Mechanics and Virtual Engineering COMEC 9 9 OCTOBER 9, Brasov, Romania KINEMATICS STUY AN WORKING SIMULATION OF THE SELF- ERECTION MECHANISM OF A SELF-ERECTING
More informationFactorization Method Using Interpolated Feature Tracking via Projective Geometry
Factorization Method Using Interpolated Feature Tracking via Projective Geometry Hideo Saito, Shigeharu Kamijima Department of Information and Computer Science, Keio University Yokohama-City, 223-8522,
More information1 Projective Geometry
CIS8, Machine Perception Review Problem - SPRING 26 Instructions. All coordinate systems are right handed. Projective Geometry Figure : Facade rectification. I took an image of a rectangular object, and
More informationLecture 19: Motion. Effect of window size 11/20/2007. Sources of error in correspondences. Review Problem set 3. Tuesday, Nov 20
Lecture 19: Motion Review Problem set 3 Dense stereo matching Sparse stereo matching Indexing scenes Tuesda, Nov 0 Effect of window size W = 3 W = 0 Want window large enough to have sufficient intensit
More informationGeometry of a single camera. Odilon Redon, Cyclops, 1914
Geometr o a single camera Odilon Redon, Cclops, 94 Our goal: Recover o 3D structure Recover o structure rom one image is inherentl ambiguous??? Single-view ambiguit Single-view ambiguit Rashad Alakbarov
More informationVisual compensation in localization of a robot on a ceiling map
Scientific Research and Essas Vol. ), pp. -, Januar, Available online at http://www.academicjournals.org/sre ISSN - Academic Journals Full Length Research Paper Visual compensation in localiation of a
More information3D Sensing and Reconstruction Readings: Ch 12: , Ch 13: ,
3D Sensing and Reconstruction Readings: Ch 12: 12.5-6, Ch 13: 13.1-3, 13.9.4 Perspective Geometry Camera Model Stereo Triangulation 3D Reconstruction by Space Carving 3D Shape from X means getting 3D coordinates
More informationVisual compensation in localization of a robot on a ceiling map
Scientific Research and Essas Vol. 6(1, pp. 131-13, 4 Januar, 211 Available online at http://www.academicjournals.org/sre DOI: 1.897/SRE1.814 ISSN 1992-2248 211 Academic Journals Full Length Research Paper
More informationA novel point matching method for stereovision measurement using RANSAC affine transformation
A novel point matching method for stereovision measurement using RANSAC affine transformation Naiguang Lu, Peng Sun, Wenyi Deng, Lianqing Zhu, Xiaoping Lou School of Optoelectronic Information & Telecommunication
More informationE V ER-growing global competition forces. Accuracy Analysis and Improvement for Direct Laser Sintering
Accurac Analsis and Improvement for Direct Laser Sintering Y. Tang 1, H. T. Loh 12, J. Y. H. Fuh 2, Y. S. Wong 2, L. Lu 2, Y. Ning 2, X. Wang 2 1 Singapore-MIT Alliance, National Universit of Singapore
More informationViewing in 3D (Chapt. 6 in FVD, Chapt. 12 in Hearn & Baker)
Viewing in 3D (Chapt. 6 in FVD, Chapt. 2 in Hearn & Baker) Viewing in 3D s. 2D 2D 2D world Camera world 2D 3D Transformation Pipe-Line Modeling transformation world Bod Sstem Viewing transformation Front-
More informationAction Detection in Cluttered Video with. Successive Convex Matching
Action Detection in Cluttered Video with 1 Successive Conve Matching Hao Jiang 1, Mark S. Drew 2 and Ze-Nian Li 2 1 Computer Science Department, Boston College, Chestnut Hill, MA, USA 2 School of Computing
More informationDense 3D Reconstruction. Christiano Gava
Dense 3D Reconstruction Christiano Gava christiano.gava@dfki.de Outline Previous lecture: structure and motion II Structure and motion loop Triangulation Today: dense 3D reconstruction The matching problem
More informationRoberto s Notes on Differential Calculus Chapter 8: Graphical analysis Section 5. Graph sketching
Roberto s Notes on Differential Calculus Chapter 8: Graphical analsis Section 5 Graph sketching What ou need to know alread: How to compute and interpret limits How to perform first and second derivative
More informationComputer Vision Lecture 17
Computer Vision Lecture 17 Epipolar Geometry & Stereo Basics 13.01.2015 Bastian Leibe RWTH Aachen http://www.vision.rwth-aachen.de leibe@vision.rwth-aachen.de Announcements Seminar in the summer semester
More informationEASY PROJECTOR AND MONOCHROME CAMERA CALIBRATION METHOD USING PLANE BOARD WITH MULTIPLE ENCODED MARKERS
EASY PROJECTOR AND MONOCHROME CAMERA CALIBRATION METHOD USING PLANE BOARD WITH MULTIPLE ENCODED MARKERS Tatsuya Hanayama 1 Shota Kiyota 1 Ryo Furukawa 3 Hiroshi Kawasaki 1 1 Faculty of Engineering, Kagoshima
More informationComputer Vision Lecture 17
Announcements Computer Vision Lecture 17 Epipolar Geometry & Stereo Basics Seminar in the summer semester Current Topics in Computer Vision and Machine Learning Block seminar, presentations in 1 st week
More informationToday s class. Geometric objects and transformations. Informationsteknologi. Wednesday, November 7, 2007 Computer Graphics - Class 5 1
Toda s class Geometric objects and transformations Wednesda, November 7, 27 Computer Graphics - Class 5 Vector operations Review of vector operations needed for working in computer graphics adding two
More informationCamera models and calibration
Camera models and calibration Read tutorial chapter 2 and 3. http://www.cs.unc.edu/~marc/tutorial/ Szeliski s book pp.29-73 Schedule (tentative) 2 # date topic Sep.8 Introduction and geometry 2 Sep.25
More informationPin Hole Cameras & Warp Functions
Pin Hole Cameras & Warp Functions Instructor - Simon Lucey 16-423 - Designing Computer Vision Apps Today Pinhole Camera. Homogenous Coordinates. Planar Warp Functions. Motivation Taken from: http://img.gawkerassets.com/img/18w7i1umpzoa9jpg/original.jpg
More informationHybrid Computing Algorithm in Representing Solid Model
The International Arab Journal of Information Technolog, Vol. 7, No. 4, October 00 4 Hbrid Computing Algorithm in Representing Solid Model Muhammad Matondang and Habibollah Haron Department of Modeling
More informationOcclusion Detection of Real Objects using Contour Based Stereo Matching
Occlusion Detection of Real Objects using Contour Based Stereo Matching Kenichi Hayashi, Hirokazu Kato, Shogo Nishida Graduate School of Engineering Science, Osaka University,1-3 Machikaneyama-cho, Toyonaka,
More information2 Stereo Vision System
Stereo 3D Lip Tracking Gareth Lo, Roland Goecke, Sebastien Rougeau and Aleander Zelinsk Research School of Information Sciences and Engineering Australian National Universit, Canberra, Australia fgareth,
More informationLucas-Kanade Image Registration Using Camera Parameters
Lucas-Kanade Image Registration Using Camera Parameters Sunghyun Cho a, Hojin Cho a, Yu-Wing Tai b, Young Su Moon c, Junguk Cho c, Shihwa Lee c, and Seungyong Lee a a POSTECH, Pohang, Korea b KAIST, Daejeon,
More informationA New Concept on Automatic Parking of an Electric Vehicle
A New Concept on Automatic Parking of an Electric Vehicle C. CAMUS P. COELHO J.C. QUADRADO Instituto Superior de Engenharia de Lisboa Rua Conselheiro Emídio Navarro PORTUGAL Abstract: - A solution to perform
More informationPart I: Single and Two View Geometry Internal camera parameters
!! 43 1!???? Imaging eometry Multiple View eometry Perspective projection Richard Hartley Andrew isserman O p y VPR June 1999 where image plane This can be written as a linear mapping between homogeneous
More informationRobot Sensing & Perception. METR 4202: Advanced Control & Robotics. Date Lecture (W: 11:10-12:40, ) 30-Jul Introduction 6-Aug
Robot Sensing & Perception Seeing is forgetting the name of what one sees L. Weschler METR 4202: Advanced Control & Robotics Dr Sura Singh -- Lecture # 6 September 3 2014 metr4202@itee.uq.edu.au http://robotics.itee.uq.edu.au/~metr4202/
More informationDESIGNING AND DEVELOPING A FULLY AUTOMATIC INTERIOR ORIENTATION METHOD IN A DIGITAL PHOTOGRAMMETRIC WORKSTATION
DESIGNING AND DEVELOPING A FULLY AUTOMATIC INTERIOR ORIENTATION METHOD IN A DIGITAL PHOTOGRAMMETRIC WORKSTATION M. Ravanbakhsh Surveing college, National Cartographic Center (NCC), Tehran, Iran, P.O.Bo:385-684
More informationGeometric Model of Camera
Geometric Model of Camera Dr. Gerhard Roth COMP 42A Winter 25 Version 2 Similar Triangles 2 Geometric Model of Camera Perspective projection P(X,Y,Z) p(,) f X Z f Y Z 3 Parallel lines aren t 4 Figure b
More informationOBSTACLE LOCALIZATION IN 3D SCENES FROM STEREOSCOPIC SEQUENCES
OBSTACLE LOCALIZATION IN 3D SCENES FROM STEREOSCOPIC SEQUENCES Piotr Skulimowski and Paweł Strumiłło Institute of Electronics, Technical Universit of Łódź 211/215 Wólcańska, 90-924, Łódź, Poland phone:
More informationA Factorization Method for Structure from Planar Motion
A Factorization Method for Structure from Planar Motion Jian Li and Rama Chellappa Center for Automation Research (CfAR) and Department of Electrical and Computer Engineering University of Maryland, College
More informationCSE 252B: Computer Vision II
CSE 252B: Computer Vision II Lecturer: Serge Belongie Scribes: Jeremy Pollock and Neil Alldrin LECTURE 14 Robust Feature Matching 14.1. Introduction Last lecture we learned how to find interest points
More informationOmni-directional Multi-baseline Stereo without Similarity Measures
Omni-directional Multi-baseline Stereo without Similarity Measures Tomokazu Sato and Naokazu Yokoya Graduate School of Information Science, Nara Institute of Science and Technology 8916-5 Takayama, Ikoma,
More informationContents. 1 Introduction Background Organization Features... 7
Contents 1 Introduction... 1 1.1 Background.... 1 1.2 Organization... 2 1.3 Features... 7 Part I Fundamental Algorithms for Computer Vision 2 Ellipse Fitting... 11 2.1 Representation of Ellipses.... 11
More informationStereo Vision. MAN-522 Computer Vision
Stereo Vision MAN-522 Computer Vision What is the goal of stereo vision? The recovery of the 3D structure of a scene using two or more images of the 3D scene, each acquired from a different viewpoint in
More informationComputer Vision I. Announcement. Stereo Vision Outline. Stereo II. CSE252A Lecture 15
Announcement Stereo II CSE252A Lecture 15 HW3 assigned No class on Thursday 12/6 Extra class on Tuesday 12/4 at 6:30PM in WLH Room 2112 Mars Exploratory Rovers: Spirit and Opportunity Stereo Vision Outline
More information3D Face Reconstruction Using the Stereo Camera and Neural Network Regression
3D Face Reconstruction Using the Stereo amera and Neural Network Regression Wen-hang heng( 鄭文昌 ) hia-fan hang( 張加璠 ) Dep. of omputer Science and Dep. of omputer Science and nformation Engineering, nformation
More informationPin Hole Cameras & Warp Functions
Pin Hole Cameras & Warp Functions Instructor - Simon Lucey 16-423 - Designing Computer Vision Apps Today Pinhole Camera. Homogenous Coordinates. Planar Warp Functions. Example of SLAM for AR Taken from:
More informationBIL Computer Vision Apr 16, 2014
BIL 719 - Computer Vision Apr 16, 2014 Binocular Stereo (cont d.), Structure from Motion Aykut Erdem Dept. of Computer Engineering Hacettepe University Slide credit: S. Lazebnik Basic stereo matching algorithm
More informationTransformations Between Two Images. Translation Rotation Rigid Similarity (scaled rotation) Affine Projective Pseudo Perspective Bi linear
Transformations etween Two Images Translation Rotation Rigid Similarit (scaled rotation) ffine Projective Pseudo Perspective i linear Fundamental Matri Lecture 13 pplications Stereo Structure from Motion
More informationEECS 556 Image Processing W 09
EECS 556 Image Processing W 09 Motion estimation Global vs. Local Motion Block Motion Estimation Optical Flow Estimation (normal equation) Man slides of this lecture are courtes of prof Milanfar (UCSC)
More informationDense 3D Reconstruction. Christiano Gava
Dense 3D Reconstruction Christiano Gava christiano.gava@dfki.de Outline Previous lecture: structure and motion II Structure and motion loop Triangulation Wide baseline matching (SIFT) Today: dense 3D reconstruction
More informationA Full Analytical Solution to the Direct and Inverse Kinematics of the Pentaxis Robot Manipulator
A Full Analtical Solution to the Direct and Inverse Kinematics of the Pentais Robot Manipulator Moisés Estrada Castañeda, Luis Tupak Aguilar Bustos, Luis A. Gonále Hernánde Instituto Politécnico Nacional
More informationFundamental Matrix. Lecture 13
Fundamental Matri Lecture 13 Transformations etween Two Images Translation Rotation Rigid Similarit (scaled rotation) ffine Projective Pseudo Perspective i linear pplications Stereo Structure from Motion
More informationDevelopment of Pseudo 3D Visualization System by Superimposing Ultrasound Images
Development of Pseudo 3D Visualization stem b uperimposing Ultrasound Images Yumi Iwashita, hinji Tarumi, Ro Kurazume Graduate chool of Information cience and Electrical Engineering Kushu Universit, Fukuoka,
More informationProjector Calibration for Pattern Projection Systems
Projector Calibration for Pattern Projection Systems I. Din *1, H. Anwar 2, I. Syed 1, H. Zafar 3, L. Hasan 3 1 Department of Electronics Engineering, Incheon National University, Incheon, South Korea.
More informationImage formation - About the course. Grading & Project. Tentative Schedule. Course Content. Students introduction
About the course Instructors: Haibin Ling (hbling@temple, Wachman 305) Hours Lecture: Tuesda 5:30-8:00pm, TTLMAN 403B Office hour: Tuesda 3:00-5:00pm, or b appointment Tetbook Computer Vision: Models,
More informationMathematics of a Multiple Omni-Directional System
Mathematics of a Multiple Omni-Directional System A. Torii A. Sugimoto A. Imiya, School of Science and National Institute of Institute of Media and Technology, Informatics, Information Technology, Chiba
More information